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<br />2. Adverse Flood Impacts and Durability <br />The CWCB takes very seriously the flood safety aspects of RICDs, and will carefully <br />consider flood safety in reviewing the RICD application.. The CWCB recommends that <br />an applicant for an RICD demonstrate, through appropriate technical analyses, that the <br />proposed boating course is designed and will be (is) constructed in such a manner as to: <br />. Adequately pass all flows up to and including the lOG-year (l'Yo probablity) flood <br />flow without causing adverse impacts to upstream, downstream or adjacent <br />property owners. Verification of "no adverse impact" can be demonstrated <br />through the use of a CWCB approved step-backwater hydraulics model such as <br />HEC-RAS. 1 <br />. Adequately withstand stream forces for all flows up to and including the lOG-year <br />flood so that damage and failure of the boating course is avoided.2 <br /> <br />3. Liability <br />The CWCB assumes no responsibility for use or misuse of the boating course and is not <br />subject to liability for injuries or damages caused therefrom. CWCB approval of or <br />recommendation to endorse an applicant's proposed RICD water right in no way implies <br />that the CWCB accepts responsibility for final design, construction, operation, and <br />safety of the boating course. <br /> <br />1 As required by current federal regulations and state floodplain management rules (not new guidance <br />developed for the purposes of this document). the applicant is advised that the proposed boating facility <br />must be analyzed for flood impacts by modeling the "existing conditions" (pre-facility) scenario and the <br />"proposed conditions" (with-facility) scenario. The hydraulic computer modeling must be performed by a <br />registered Professional Engineer (Colorado Registration) having expertise in surface water hydraulic <br />modeling. Impacts that should be analyzed include increases in water surface elevations for the range of <br />flows experienced at the proposed recreational facility. but especially the lOO-year flood event. <br />According to federal regulations. water surface elevations at the proposed RICD facility may not increase <br />at all (zero rise) in the event that the proposed recreational facility is within a stream reach having a <br />designated Floodway (the most hazardous portion within the lOO-year floodplain). For reaches that are <br />not within a designated Floodway. any increases in the lOO-year flood profile for the proposed RICD <br />facility (up to a maximum of one foot or a lesser amount specified by local floodplain ordinances or codes. <br />whichever is more restrictive) must be documented. Proper notification of adverse impacts (increased <br />water surface elevations) must be provided to affected property owners and a Letter of Map Revision <br />(LOMR) should be obtained as required by FEMA for National Flood Insurance Program purposes. <br /> <br />ZIt is recommended that the boating course consist of appropriate materials and installation to endure <br />velocities. shear stresses. other erosive conditions. sedimentation. and debris that would be experienced <br />during the range of expected flows and high flow (flood) conditions. For example. a boulder drop <br />structure should be constructed with material having suitable size. hardness. shape and gradation and <br />c:hnlllrl hp_ inc:tnllp.r1 in C:llrh n mnt'lt'lP.r thnt it ic: nt'lrhnrp.r1 intn thp_ c:trp.nm hnnk nnrl c:trp.nmhprl tn C:llrvivp <br />~~-- - ------~,.";i~j< I.-a' "---~---~.....",,:_ ----- ---------------------- ------------ .-----------~ . -~.- <br />-liiiiiiioo/ <br />---_.~ <br /> <br />~~ <br /> <br />